U.S. patent application number 12/991199 was filed with the patent office on 2011-05-19 for glutathione production enhancer, prophylactic/therapeutic agent for diseases caused by glutathione deficiency, and food, beverage and feed.
This patent application is currently assigned to MARUZEN PHARMACEUTICALS.,LTD.. Invention is credited to Toshiyuki Murakami, Hirokazu Ohno, Nobuaki Ohto.
Application Number | 20110118201 12/991199 |
Document ID | / |
Family ID | 41264667 |
Filed Date | 2011-05-19 |
United States Patent
Application |
20110118201 |
Kind Code |
A1 |
Ohto; Nobuaki ; et
al. |
May 19, 2011 |
GLUTATHIONE PRODUCTION ENHANCER, PROPHYLACTIC/THERAPEUTIC AGENT FOR
DISEASES CAUSED BY GLUTATHIONE DEFICIENCY, AND FOOD, BEVERAGE AND
FEED
Abstract
The invention aims at finding a highly-safe natural product
having glutathione production-enhancing activity, and providing a
glutathione production enhancer and a prophylactic/therapeutic
agent for diseases caused by glutathione deficiency using that
natural product as an active ingredient. The glutathione production
enhancer or the prophylactic/therapeutic agent for diseases caused
by glutathione deficiency contains, as an active ingredient, a
licorice extract composition that contains liquiritin,
liquiritigenin, isoliquiritin and isoliquiritigenin but contains
substantially no glycyrrhizic acid.
Inventors: |
Ohto; Nobuaki; (Hiroshima,
JP) ; Murakami; Toshiyuki; (Hiroshima, JP) ;
Ohno; Hirokazu; (Hiroshima, JP) |
Assignee: |
MARUZEN
PHARMACEUTICALS.,LTD.
Hiroshima
JP
|
Family ID: |
41264667 |
Appl. No.: |
12/991199 |
Filed: |
May 1, 2009 |
PCT Filed: |
May 1, 2009 |
PCT NO: |
PCT/JP2009/058586 |
371 Date: |
January 11, 2011 |
Current U.S.
Class: |
514/35 |
Current CPC
Class: |
A61P 35/00 20180101;
A61K 36/484 20130101; A61P 7/00 20180101; A23K 20/121 20160501;
A23L 33/105 20160801; A61P 25/16 20180101; A61P 31/12 20180101;
A61P 37/04 20180101; A61P 37/02 20180101; A61K 31/7034 20130101;
A61P 9/10 20180101; A61P 11/00 20180101; A61K 31/12 20130101; A61K
31/7048 20130101; A61P 27/12 20180101; A23K 20/105 20160501; A61P
39/06 20180101; A61P 1/04 20180101; A61P 1/16 20180101; A61P 13/12
20180101; A61P 43/00 20180101; A61P 25/28 20180101; A61K 31/382
20130101; A61P 25/00 20180101 |
Class at
Publication: |
514/35 |
International
Class: |
A61K 31/7048 20060101
A61K031/7048; A61P 1/16 20060101 A61P001/16; A61P 13/12 20060101
A61P013/12; A61P 25/28 20060101 A61P025/28; A61P 25/16 20060101
A61P025/16; A61P 11/00 20060101 A61P011/00; A61P 9/10 20060101
A61P009/10; A61P 1/04 20060101 A61P001/04; A61P 39/06 20060101
A61P039/06; A61P 37/02 20060101 A61P037/02 |
Foreign Application Data
Date |
Code |
Application Number |
May 9, 2008 |
JP |
2008-123941 |
Claims
1. A glutathione production enhancer, comprising, as an active
ingredient, a licorice extract composition that contains
liquiritin, liquiritigenin, isoliquiritin and isoliquiritigenin but
contains substantially no glycyrrhizic acid.
2. A prophylactic/therapeutic agent for diseases caused by
glutathione deficiency, comprising, as an active ingredient, a
licorice extract composition that contains liquiritin,
liquiritigenin, isoliquiritin and isoliquiritigenin but contains
substantially no glycyrrhizic acid.
3. A food and beverage, comprising a licorice extract composition
that contains liquiritin, liquiritigenin, isoliquiritin and
isoliquiritigenin but contains substantially no glycyrrhizic
acid.
4. A feed, comprising a licorice extract composition that contains
liquiritin, liquiritigenin, isoliquiritin and isoliquiritigenin but
contains substantially no glycyrrhizic acid.
5. A method for promoting glutathione production in human cells in
vivo or animal cells in vivo, comprising: administering, to a
predetermined site of a human or an animal, a glutathione
production enhancer containing a licorice extract composition that
contains liquiritin, liquiritigenin, isoliquiritin and
isoliquiritigenin but contains substantially no glycyrrhizic
acid.
6. A method for manufacturing a licorice extract composition that
contains liquiritin, liquiritigenin, isoliquiritin and
isoliquiritigenin but contains substantially no glycyrrhizic acid,
comprising: substantially removing glycyrrhizic acid from a
licorice extract.
Description
TECHNICAL FIELD
[0001] The present invention relates to a glutathione production
enhancer, prophylactic/therapeutic agent for diseases caused by
glutathione deficiency, and food, beverage and feed.
BACKGROUND ART
[0002] Glutathione is a tripeptide comprising three amino acids,
namely glutamic acid, cysteine and glycine, and is a major cysteine
residue-containing compound in cells. As is known, glutathione
plays various roles in cells, for instance contributing to radical
scavenging, redox-mediated regulation of cell function, and
detoxifying mechanisms, as well as serving as a SH-donor for
various enzymes.
[0003] Decreases in the intra-cellular concentration of glutathione
that plays these roles are known to give rise to conditions such as
cell damage due to ultraviolet radiation exposure, inflammation,
blackening, formation of freckles and blemishes, acute or chronic
alcohol-derived liver damage, liver disease, chronic renal failure,
lung diseases caused by smoking, idiopathic pulmonary fibrosis,
cataracts, ischemic heart disease, Parkinson's disease, Alzheimer's
disease, gastric ulcer, adult respiratory syndrome,
immunodeficiency, bone-marrow aplasia, acquired immunodeficiency
syndrome, latent viral infections, aging phenomena derived from
physiological aging, as well as oncogenesis. Conventional
approaches to treat conditions caused by low concentration of
glutathione in cells have involved using glutathione formulations
that contain glutathione, with a view to eliciting uptake of
glutathione by cells having a lowered intracellular glutathione
concentration (Patent Document 1). However, therapy relying on oral
ingestion of glutathione formulations may fail to elicit the
anticipated effects, depending on the affected area to be treated.
Although arguably more effective than oral ingestion, therapies by
intravenous injection of glutathione formulations were problematic
in that, for instance, injection is painful, and requires hospital
visits.
[0004] Therefore, an increase in the intracellular glutathione
concentration through promotion of glutathione production of cells
in vivo should conceivably allow increasing defenses against
oxidative stress, which decline with age, suppressing damage from
oxidative stress caused by ultraviolet radiation, and preventing,
treating or improving various diseases that include, for instance,
skin aging, pigmentation disorders such as blemishes, and
preventing and/or treating various organ dysfunctions and various
diseases caused by glutathione deficiency. Known extraction
products based on the above concept and having glutathione
production-enhancing activity include, for instance, bilberry
extraction products and walnut extraction products (Patent document
2), and extraction products of plants of the genus Gardenia (Patent
document 3).
[0005] Glutathione is present in the organism in the form of
reduced glutathione, which has the effect of removing reactive
oxygen species, and oxidized glutathione, which is formed through
reaction of reduced glutathione and reactive oxygen species. In
recent years it has been found that oxidized glutathione is a
sleep-promoting substance that promotes sleep by inhibiting
neuronal excitability. Therefore, promoting glutathione production
and increasing intracellular concentration, not only of reduced
glutathione but also of oxidized glutathione, should conceivably be
effective for preventing, treating or improving sleep disorders
such as insomnia. Known sleep-inducing agents based on this concept
include agents using oxidized glutathione as an active ingredient
(Patent document 4).
[0006] In living cells, .gamma.-glutamylcysteine is biosynthesized
through reaction of glutamic acid and cysteine, mediated by
.gamma.-glutamylcysteine synthetase. As is known, glutathione is
biosynthesized through reaction of .gamma.-glutamylcysteine and
glycine, mediated by glutathione synthetase. Therefore, the
glutathione concentration of cells in vivo could be conceivably
increased by promoting the expression of .gamma.-glutamylcysteine
synthetase, which acts as a catalyst in the biosynthesis of
.gamma.-glutamylcysteine as the precursor of glutathione.
[0007] Patent document 1: WO 2003/032966
[0008] Patent document 2: JP 2006-241062 A
[0009] Patent document 3: JP 2006-347934 A
[0010] Patent document 4: JP 4-9336 A
DISCLOSURE OF THE INVENTION
[0011] It is an object of the present invention to find highly-safe
natural products having glutathione production-enhancing activity
and .gamma.-glutamylcysteine synthetase mRNA expression promotion
activity, and to provide a glutathione production enhancer,
prophylactic/therapeutic agent for diseases caused by glutathione
deficiency, food and beverage, and feed, that have that natural
product as an active ingredient.
[0012] In order to solve the above problem, a glutathione
production enhancer and a prophylactic/therapeutic agent for
diseases caused by glutathione deficiency of the present invention
comprise, as an active ingredient, a licorice extract composition
that contains liquiritin, liquiritigenin, isoliquiritin and
isoliquiritigenin but contains substantially no glycyrrhizic
acid.
[0013] A food and beverage and a feed of the present invention,
comprise a licorice extract composition that contains liquiritin,
liquiritigenin, isoliquiritin and isoliquiritigenin but contains
substantially no glycyrrhizic acid.
[0014] Further, a method for promoting glutathione production in
human cells in vivo or animal cells in vivo, of the present
invention comprises administering, to a predetermined site of a
human or an animal, a glutathione production enhancer containing a
licorice extract composition that contains liquiritin,
liquiritigenin, isoliquiritin and isoliquiritigenin but contains
substantially no glycyrrhizic acid.
[0015] Further, a method for manufacturing a licorice extract
composition that contains liquiritin, liquiritigenin, isoliquiritin
and isoliquiritigenin but contains substantially no glycyrrhizic
acid of the present invention comprises substantially removing
glycyrrhizic acid from a licorice extract.
[0016] In the present invention, the term "containing substantially
no glycyrrhizic acid" means that the glycyrrhizic acid content in
the licorice extract composition is preferably no greater than 1.0
wt %, more preferably no greater than 0.5 wt %.
[0017] In the present invention, the term "licorice extract" means
a liquid extracted using licorice as an extract raw material, a
diluted or concentrated liquid of the liquid extract, or a dry
product obtained by drying the liquid extract, and from which
glycyrrhizic acid is not substantially removed. The "licorice
extract composition" means a composition from which glycyrrhizic
acid is substantially removed, and that contains liquiritin,
liquiritigenin, isoliquiritin and isoliquiritigenin.
[0018] The present invention allows providing a glutathione
production enhancer, a prophylactic/therapeutic agent for diseases
caused by glutathione deficiency, a food and beverage, and a feed
having excellent safety and containing, as an active ingredient, a
licorice extract composition that comprises liquiritin,
liquiritigenin, isoliquiritin and isoliquiritigenin but
substantially no glycyrrhizic acid.
BEST MODE FOR CARRYING OUT THE INVENTION
[0019] Embodiments of the present invention are explained
below.
[0020] [Glutathione Production Enhancer, Prophylactic/Therapeutic
Agent Diseases Caused by Glutathione Deficiency]
[0021] The glutathione production enhancer and the
prophylactic/therapeutic agent for diseases caused by glutathione
deficiency of the present embodiment contain, as an active
ingredient, a licorice extract composition that contains
liquiritin, liquiritigenin, isoliquiritin and isoliquiritigenin but
contains substantially no glycyrrhizic acid (hereafter, simply
"licorice extract composition").
[0022] The licorice extract composition containing liquiritin,
liquiritigenin, isoliquiritin and isoliquiritigenin but containing
substantially no glycyrrhizic acid can be obtained by removing
glycyrrhizic acid from a licorice extract that can be obtained in
accordance with methods ordinarily used in plant extraction
processes.
[0023] Examples of licorice as the extract raw material include,
for instance, various species such as Glycyrrhiza glabra,
Glycyrrhiza inflata, Glycyrrhiza uralensis, Glycyrrhiza aspera,
Glycyrrhiza eurycarpa, Glycyrrhiza pallidiflora, Glycyrrhiza
yunnanensis, Glycyrrhiza lepidota, Glycyrrhiza echinata,
Glycyrrhiza acanthocarpa or the like. Any licorice species from
among the foregoing may be used as the extract raw material. In
particular, Glycyrrhiza glabra, Glycyrrhiza uralensis or
Glycyrrhiza inflata is preferably used as the extract raw
material.
[0024] The constituent portion of licorice that can be used as the
extract raw material may include, for instance, aerial portions
such as leaves, branches, barks, trunks, stems, fruits or flowers;
as well as roots, rhizomes, and mixtures of the foregoing,
preferably roots or rhizomes.
[0025] The licorice extract can be obtained by drying licorice as
the extract raw material, followed by extraction of the dried
licorice, as-is or ground using a coarse crusher, in an extraction
solvent. Drying may involve air drying or drying using an
ordinarily employed dryer. As the extract raw material licorice may
also be used, for instance, after having subjected to a
pre-treatment, for instance defatting using a non-polar solvent
such as hexane. A pre-treatment such as defatting or the like
allows carrying out the plant extraction using a polar solvent yet
more efficiently.
[0026] Preferably, a polar solvent such as water, a hydrophilic
organic solvent or the like is used as the extraction solvent. The
polar solvent is used singly or in combinations of two or more, and
is used preferably at room temperature or a temperature not higher
than the boiling point of the solvent.
[0027] Examples of water that can be used as the extraction solvent
include, for instance, pure water, tap water, well water, mineral
spring water, mineral water, hot-spring water, spring water and
fresh water, as well as water resulting from treating the foregoing
in various ways. Examples of water treatment process include, for
instance, purification, heating, sterilization, filtration,
deionization, osmotic adjustment, acidification, alkalinization,
buffering and the like. Therefore, examples of water that can be
used as the extraction solvent in the present embodiment include,
for instance, purified water, hot water, deionized water, saline
water, organic acid water, ammonia alkaline water, phosphate
buffered solution, phosphate buffered salines or the like.
[0028] Examples of the hydrophilic organic solvent that can be used
as the extraction solvent include, for instance, C1-C5 lower
aliphatic alcohols such as methanol, ethanol, propyl alcohol and
isopropyl alcohol; a lower aliphatic ketone such as acetone or
methyl ethyl ketone; and C2-C5 polyhydric alcohols such as
1,3-butylene glycol, propylene glycol or glycerin.
[0029] If the extraction solvent is used in the form of a mixed
liquid of two or more types of polar solvent, the mixing ratio of
the foregoing can be adjusted appropriately. For instance, in a
case where a mixed liquid of water and a lower aliphatic alcohol is
used, the mixture comprises preferably 1 to 90 parts by volume of
lower aliphatic alcohol with respect to 10 parts by volume of
water; in a case where a mixed liquid of water and a lower
aliphatic ketone is used, the mixture comprises preferably 1 to 40
parts by volume of lower aliphatic ketone with respect to 10 parts
by volume of water; in a case where a mixed liquid of water and a
polyhydric alcohol is used, the mixture comprises preferably 10 to
90 parts by volume of polyhydric alcohol with respect to 10 parts
by volume of water.
[0030] The extraction process is not particularly limited, provided
that the soluble component comprised in the extract raw material
can be eluted by the extraction solvent, and thus the extraction
process may be carried out in accordance with ordinary methods. For
instance, the extract raw material is immersed in 5 to 15 volumes
(weight ratio) of extraction solvent, and the soluble component is
extracted at normal temperature or under reflux heating. The liquid
extract can be obtained then by removing the extraction residue by
filtering. A paste-like concentrate is obtained upon evaporating of
the solvent off the obtained liquid extract. This concentrate is
further dried to yield a dry product.
[0031] The liquid extract, the concentrate of the liquid extract,
or the dry product of the liquid extract, obtained as described
above, contain the flavonoids liquiritin, liquiritigenin,
isoliquiritin and isoliquiritigenin, and also glycyrrhizic acid.
Therefore, glycyrrhizic acid is removed from the liquid extract,
the concentrate of the liquid extract, or the dry product (licorice
extract) of the liquid extract.
[0032] To remove glycyrrhizic acid from the licorice extract, an 80
to 95 vol % alcohol-water solution is added to the licorice
extract, the extraction product from the licorice is dispersed into
the alcohol-water solution, and is then suction-filtered with
filter paper. Glycyrrhizic acid is soluble in water but poorly
soluble in alcohol. Therefore, glycyrrhizic acid comprised in the
licorice extract virtually does not dissolve in the alcohol-water
solution, and is removed as a precipitate. By contrast, liquiritin,
liquiritigenin, isoliquiritin and isoliquiritigenin are soluble in
alcohol, and dissolve readily in the alcohol-water solution.
[0033] The alcohol used as the dispersion medium is not
particularly limited, and may be, for instance, a C1-C5 lower
aliphatic alcohol such as methanol, ethanol, propyl alcohol or
isopropyl alcohol.
[0034] Water is added to the residue formed by evaporating the
solvent off the obtained filtrate, followed by column
chromatography using a porous substance such as silica gel, alumina
or the like, or a porous resin such as a styrene-divinylbenzene
copolymer or polymethacrylate, with sequential elution with water
and alcohol. A licorice extract composition is obtained thus in the
form of the fraction eluted with alcohol, which contains
liquiritin, liquiritigenin, isoliquiritin and isoliquiritigenin but
contains substantially no glycyrrhizic acid.
[0035] The alcohol used as the eluent in column chromatography is
not particularly limited, and may be, for instance, a C1-C5 lower
aliphatic alcohol such as methanol, ethanol, propyl alcohol or
isopropyl alcohol, or a solution of the foregoing in water.
[0036] The alcohol fraction obtained by column chromatography may
be further purified in accordance with any organic compound
purification method, for instance reverse-phase silica gel
chromatography using ODS, recrystallization, liquid-liquid
countercurrent extraction, or column chromatography using an
ion-exchange resin.
[0037] Other than the above-described method, the methods described
below may also be used for removing glycyrrhizic acid from a
licorice extract and obtain thereby a licorice extract composition
containing liquiritin, liquiritigenin, isoliquiritin and
isoliquiritigenin but containing substantially no glycyrrhizic
acid.
[0038] For instance, a mineral acid (such as sulfuric acid, nitric
acid, hydrochloric acid or the like) is added to the licorice
extract, to adjust pH from about 1.0 to 3.0, and elicit thereby
acid precipitation. The obtained acid precipitation solution is
filtered to recover the precipitate. To the latter there is added a
30 to 90 vol %, preferably 30 to 70 vol % alcohol-water solution
(aqueous solution of a C1-C5 lower aliphatic alcohol such as
methanol, ethanol, propyl alcohol or isopropyl alcohol), followed
by filtering.
[0039] The pH of the filtrate thus obtained is adjusted to about
3.0 to 5.0, preferably about 3.0 to 3.5, using aqueous ammonia, to
cause glycyrrhizic acid to precipitate, followed by solid-liquid
separation. The obtained filtrate fraction is neutralized through
addition of sodium carbonate. This is followed by column
chromatography using a porous substance such as silica gel, alumina
or the like, or a porous resin such as a styrene-divinylbenzene
copolymer or polymethacrylate, with sequential elution with water
and alcohol. A licorice extract composition is obtained thus in the
form of the fraction eluted with alcohol, which contains
liquiritin, liquiritigenin, isoliquiritin and isoliquiritigenin but
contains substantially no glycyrrhizic acid. The alcohol used as
the eluent in column chromatography may be the same as the
above-described ones.
[0040] The alcohol fraction obtained by column chromatography may
be further purified in accordance with any organic compound
purification method, for instance reverse-phase silica gel
chromatography using ODS, recrystallization, liquid-liquid
countercurrent extraction, or column chromatography using an
ion-exchange resin.
[0041] The licorice extract composition containing liquiritin,
liquiritigenin, isoliquiritin and isoliquiritigenin but containing
substantially no glycyrrhizic acid can be obtained by removing
glycyrrhizic acid from the licorice extract, as described above.
The content of glycyrrhizic acid, i.e. licorice extract composition
is preferably no greater than 1.0 wt %, more preferably no greater
than 0.5 wt %.
[0042] The licorice extract composition containing liquiritin,
liquiritigenin, isoliquiritin and isoliquiritigenin but containing
substantially no glycyrrhizic acid thus obtained has glutathione
production-enhancing activity, and can therefore be used, thanks to
that effect, as an active ingredient of a glutathione production
enhancer. The licorice extract composition has also
.gamma.-glutamylcysteine synthetase mRNA expression promotion
activity, and hence can be used, thanks to that effect, as an
active ingredient of a .gamma.-glutamylcysteine synthetase mRNA
expression enhancer.
[0043] Thanks to its glutathione production-enhancing activity, the
licorice extract composition can promote the production of
glutathione, and therefore can be used as the active ingredient of
a prophylactic/therapeutic agent for diseases caused by glutathione
deficiency (for instance, diseases caused by oxidative stress from
reactive oxygen species or the like; liver diseases such as
hepatitis and liver dysfunction; chronic renal failure; respiratory
diseases such as idiopathic pulmonary fibrosis or adult respiratory
syndrome; cataracts; ischemic heart disease; Parkinson's disease;
Alzheimer's disease; gastrointestinal diseases such as gastric
ulcer; cancer; bone marrow aplasia; acquired immunodeficiency
syndrome; latent viral infections and the like).
[0044] Further, the licorice extract composition has glutathione
production-enhancing activity, and, thanks to that effect, allows
raising the intracellular concentration of oxidized glutathione.
Therefore, the licorice extract composition can also be used as an
active ingredient in preventive, therapeutic or improving agents
for sleep disorders such as insomnia.
[0045] The glutathione production enhancer or the
prophylactic/therapeutic agent for diseases caused by glutathione
deficiency of the present embodiment may comprise the licorice
extract composition alone, or a preparation formulated with the
licorice extract composition.
[0046] The licorice extract composition can be formulated any form,
for instance in powder, granule, tablet or liquid form, according
to ordinary methods, using pharmaceutically acceptable carriers
such as dextrins, cyclodextrins or the like, and arbitrary
auxiliary agents of the carriers. As such auxiliary agents there
can be used, for instance, excipients, binders, disintegrating
agents, lubricants, stabilizers, flavoring agents, odor-improving
agents and the like. The licorice extract composition can be used
blended with other compositions (for instance, food and beverages),
and can also be used as an ointment, topical solution, adhesive
patch or the like.
[0047] The glutathione production enhancer and the
prophylactic/therapeutic agent for diseases caused by glutathione
deficiency of the present embodiment can be used as an active
ingredient, as the case may require, blended with for instance
another natural extraction product having glutathione
production-enhancing activity.
[0048] The method for administering the glutathione production
enhancer or the prophylactic/therapeutic agent for diseases caused
by glutathione deficiency of the present embodiment may involve,
for instance, administration to a predetermined site of a human or
an animal, ordinarily by transdermal administration, oral
administration, intravenous administration or the like. A method
appropriate for preventing or treating a disease of interest may be
appropriately selected in accordance with the type of the disease.
Preferably, in particular, the glutathione production enhancer or
the prophylactic/therapeutic agent for diseases caused by
glutathione deficiency is administered by transdermal or oral
administration.
[0049] The administration amount of the glutathione production
enhancer and the prophylactic/therapeutic agent for diseases caused
by glutathione deficiency of the present embodiment may be dosed in
accordance with, for instance, the type of disease, the severity
thereof, individual patient differences, the administration method
and the administration period. An effective amount of the
glutathione production enhancer or the prophylactic/therapeutic
agent for diseases caused by glutathione deficiency of the present
embodiment may be administered in accordance with, for instance,
the type and severity of the disease.
[0050] By virtue of the glutathione production-enhancing activity
of the licorice extract composition, the glutathione production
enhancer of the present embodiment allows increasing defenses
against oxidative stress, which decline with age, allows
suppressing damage from oxidative stress caused by ultraviolet
radiation, and allows preventing, treating or improving various
diseases that include, for instance, skin aging, pigmentation
disorders such as blemishes, and various organ dysfunctions caused
by glutathione deficiency. Besides the above applications, the
glutathione production enhancer of the present embodiment can also
be used in all relevant applications for exerting glutathione
production-enhancing activity.
[0051] As explained in below-described examples, the licorice
extract composition, in particular, can promote effectively
production of glutathione in epidermal keratinocytes and dermal
fibroblasts. The glutathione production enhancer containing the
licorice extract composition can eliminate reactive oxygen species
in epidermal keratinocytes and dermal fibroblasts, allows
protecting epidermal keratinocytes and dermal fibroblasts against
damage caused by oxidative stress, and as a result allows
preventing effectively, for instance, skin aging.
[0052] Glutathione has the effect of inhibiting maturation of
tyrosinase. Promoting the production of glutathione allows thus
further inhibiting tyrosinase maturation, and allows inhibiting
generation of melanin by melanocytes. As a result, the glutathione
production enhancer containing the licorice extract composition
allows promoting effectively glutathione production in melanocytes,
and further inhibiting tyrosinase maturation. This allows
preventing, as a result, skin pigmentation disorders, skin
blackening, blemishes, freckles and the like.
[0053] The licorice extract composition promotes effectively
glutathione production in hepatocytes. Therefore, the glutathione
production enhancer containing the licorice extract composition
allows preventing and/or treating effectively liver diseases caused
by glutathione deficiency.
[0054] Thanks to the .gamma.-glutamylcysteine synthetase mRNA
expression promotion activity of the licorice extract composition,
biosynthesis of .gamma.-glutamylcysteine, which is a precursor of
glutathione, can be promoted by incorporating the licorice extract
composition into the .gamma.-glutamylcysteine synthetase mRNA
expression enhancer.
[0055] Thanks to the glutathione production-enhancing activity of
the licorice extract composition, the prophylactic/therapeutic
agent for diseases caused by glutathione deficiency of the present
embodiment allows preventing and/or treating diseases caused by
glutathione deficiency (for instance, diseases caused by oxidative
stress from reactive oxygen species or the like; liver diseases
such as hepatitis and liver dysfunction; chronic renal failure;
respiratory diseases such as idiopathic pulmonary fibrosis or adult
respiratory syndrome; cataracts; ischemic heart disease;
Parkinson's disease; Alzheimer's disease; gastrointestinal diseases
such as gastric ulcer; cancer; bone marrow aplasia; acquired
immunodeficiency syndrome; latent viral infections and the like),
and allows raising the intracellular concentration of oxidized
glutathione, being as a result effective for preventing, treating
or improving sleep disorders such as insomnia.
[0056] [Food and Beverage, Feed]
[0057] The food and beverage or feed of the present embodiment is
blended with a licorice extract composition that contains
liquiritin, liquiritigenin, isoliquiritin and isoliquiritigenin but
contains substantially no glycyrrhizic acid.
[0058] The licorice extract composition has glutathione
production-enhancing activity, and has proved not to be digested in
the gastrointestinal tract of, for instance, humans, animals and
fish. The licorice extract composition has also excellent safety,
and can therefore be appropriately blended with any food or drink,
such as general foods, health food, health-promoting food, dietary
supplements and the like; animal feed such as poultry or livestock
feed, fish feed for farmed fish or the like; as well as feed in the
form of pet food such as cat food, dog food or the like. In this
case, the licorice extract composition may be blended as-is into
the food, beverage or feed. Alternatively, a glutathione production
enhancer or prophylactic/therapeutic agent for diseases caused by
glutathione deficiency, formulated with the licorice extract
composition, may be blended into the food, beverage or feed.
[0059] When the licorice extract composition, the glutathione
production enhancer or the prophylactic/therapeutic agent for
diseases caused by glutathione deficiency are blended into a food
or beverage, the blending amount of active ingredient in the food
or beverage can be appropriately adjusted in accordance with, for
instance, the intended use, sex, symptoms and the like. However,
the daily ingestion amount of extraction product is preferably set
so as to range from about 1 to 1000 mg per day for adults, in
consideration of the ordinary ingestion amount of the food and
beverage to which the above are added.
[0060] The blending proportion of the licorice extract composition,
the glutathione production enhancer or the prophylactic/therapeutic
agent for diseases caused by glutathione deficiency when the
foregoing are blended into feed can be appropriately adjusted in
accordance with, for instance, the target organism (poultry,
livestock, farmed fish, or pets such as cats and dogs), the body
weight, intended purpose and so forth, but ranges preferably from
0.0001 to 20.0 wt %, more preferably from 0.01 to 2.0 wt %, in
consideration of the ordinary ingestion amount of the feed to which
the above are added.
[0061] The food and beverage into which the licorice extract
composition, the glutathione production enhancer or
prophylactic/therapeutic agent for diseases caused by glutathione
deficiency can be blended is not particularly limited, so long as
the glutathione production-enhancing activity of the licorice
extract composition is unimpeded.
[0062] Specifically, the licorice extract composition, the
glutathione production enhancer or the prophylactic/therapeutic
agent for diseases caused by glutathione deficiency can be blended
into, for instance, beverages (including undiluted concentrates and
powders for preparation) such as soft drinks, carbonated drinks,
nutritional drinks, fruit drinks, fermented lactic drinks ; frozen
desserts such as ice cream, ice sherbets, shaved ice or the like;
noodles such as soba, udon, harusame, gyoza wraps, shumai wraps,
Chinese noodles, instant noodles and the like; confectionery such
as sweets, chewing gum, candy, gum, chocolate, confectionery
tablets, snacks, biscuits, jelly, jam, cream, baked confectionery
or the like; processed marine and livestock products such as fish
paste, ham, sausage or the like; dairy products such as processed
milk, fermented milk or the like; oil, fats and oil-fat processed
foods such as salad oil, tempura oil, margarine, mayonnaise,
shortenings, whipped cream, dressings and the like; seasonings such
as sauces, dips or the like; soups, stews, salads, side dishes,
pickles; health products and supplements in various forms; as well
as tablets, capsules and tonic drinks. The licorice extract
composition, the glutathione production enhancer or the
prophylactic/therapeutic agent for diseases caused by glutathione
deficiency can be concomitantly used with other auxiliary raw
materials and additives used in the foregoing foods and
beverages.
EXAMPLES
[0063] The present invention will be explained in more detail below
by way of preparation examples, experimental examples and blending
examples. However, the present invention is not limited to these
examples in any way.
Preparation Example 1
[0064] Herein, 10 L of water were added to 10 kg of crushed chips
of licorice (Glycyrrhiza glabra) rhizomes, and extraction was
carried out under gentle stirring, followed by solid-liquid
separation by decantation, to yield a liquid extract. The obtained
liquid extract was concentrated under vacuum to a paste-like
consistency, after which 10 volumes of a 70 vol % ethanol-water
solution were added to the obtained concentrate, and the whole was
dispersed using a stirrer. The dispersion was kept at 5.degree. C.
overnight, the resulting precipitate was removed by
suction-filtering using filter paper, and the ethanol-water
solution was evaporated from the filtrate under reduced
pressure.
[0065] Water was added to the residue thus obtained, to a solids
fraction of 5%, and the whole was passed, at SV=1, through a column
packed with 10 L of a porous synthetic adsorption resin (Diaion
HP-20, by Mitsubishi Chemical). The column was washed with 50 L of
water, and then 50 L of an 80 vol % ethanol-water solution was
applied to the column to elute the flavonoids. The eluates were
collected, and were vacuum-distilled to vaporize the ethanol-water
solution off. Thereafter, the distillation residue was vacuum-dried
at 40.degree. C. and was crushed, to yield 345 g of a yellow-brown
powder (sample 1).
[0066] The obtained powder was analyzed by high performance liquid
chromatography under the below-described conditions. The results
were glycyrrhizic acid content 0.5 wt %, liquiritin content 4.2 wt
%, isoliquiritin content 3.6 wt %, liquiritigenin content 2.5 wt %,
isoliquiritigenin content 1.5 wt %.
[0067] <Liquid Chromatography Conditions>
[0068] Stationary phase: JAIGEL GS-310 (by Japan Analytical
Industry)
[0069] Column diameter: 20 mm
[0070] Column length: 500 mm
[0071] Mobile phase flow rate: 5 mL/min
[0072] Detection: RI
Preparation Example 2
[0073] Herein, 410 g of a yellow-brown powder (sample 2) were
obtained in the same way as in Example 1, but in this case there
were added 10 L of 3% aqueous ammonia to 10 kg of crushed chips of
licorice (Glycyrrhiza uralensis) rhizomes. The obtained powder was
analyzed by high performance liquid chromatography in the same way
as in Example 1. The results were glycyrrhizic acid content 0.9 wt
%, liquiritin content 5.5 wt %, isoliquiritin content 4.6 wt %,
liquiritigenin content 3.9 wt %, isoliquiritigenin content 3.5 wt
%.
Preparation Example 3
[0074] Herein, 10 L of water were added to 10 kg of crushed chips
of licorice (Glycyrrhiza inflata) rhizomes, and extraction was
carried out under gentle stirring, followed by solid-liquid
separation by decantation, to yield a liquid extract. The pH of the
obtained liquid extract was adjusted to 2 through addition of 50%
sulfuric acid, under stirring, to carry out an acid precipitation
treatment. The precipitate was filtered and collected. Water was
added to the obtained precipitate, and the whole was dispersed
under stirring and was left to stand, after which the supernatant
was removed by decantation. The above operation was repeated to
remove the sulfuric acid, after which a precipitate was obtained
through filtering.
[0075] Next, 5 L of 90 vol % ethanol were added to the precipitate
thus obtained, and the whole was dispersed through stirring for 1
hour at normal temperature, followed by suction-filtering using
diatomaceous earth. Aqueous ammonia was added to the obtained
filtrate to adjust the pH of the latter to 5. The whole was left to
stand at 5.degree. C. for 2 days, to precipitate the glycyrrhizic
acid. Thereafter, solid-liquid separation was carried out by
centrifugation. The ethanol in the filtrate fraction was removed by
vacuum distillation, and the distillation residue was neutralized
with sodium carbonate.
[0076] The neutralized solution thus obtained was passed, at SV=1,
through a column packed with 5 L of a porous synthetic adsorption
resin (Diaion HP-20, by Mitsubishi Chemical). The column was washed
with 25 L of water, and then 25 L of a 90 vol % ethanol-water
solution was applied to the column to elute the flavonoids. The
eluates were collected, and were vacuum-distilled to vaporize the
ethanol-water solution off. Thereafter, the distillation residue
was vacuum-dried at 40.degree. C. and was crushed, to yield 293 g
of a yellow-brown powder (sample 3)
[0077] The obtained powder was analyzed by high performance liquid
chromatography in the same way as in Example 1. The results were
glycyrrhizic acid content 0.8 wt %, liquiritin content 3.5 wt %,
isoliquiritin content 2.8 wt %, liquiritigenin content 2.5 wt %,
isoliquiritigenin content 1.8 wt %.
Experimental Example 1
Test of Glutathione Production-Enhancing Activity in Epidermal
Keratinocytes
[0078] The glutathione production-enhancing activity of the
licorice extract compositions obtained as described above (samples
1 to 3) was tested as described below.
[0079] Normal human epidermal keratinocytes (NHEK) were cultured
using a culture medium for long-term culture of normal human
epidermal keratinocytes (EpiLife-KG2), after which the cells were
collected by trypsinization. The collected cells were diluted with
EpiLife-KG2, to a cell density of 1.0.times.10.sup.5 cells/mL.
Thereafter, a 48-well plate was seeded with 200 .mu.L of cells per
well, and the cells were incubated overnight.
[0080] After incubation, 200 .mu.L of the sample solution dissolved
in EpiLife-KG2 (samples 1 to 3, sample concentration as per Table 1
below) were added to each well, followed by incubation for 24
hours. Once incubation was over, the medium was removed from the
wells, and each well was washed with 400 .mu.L of PBS (-). The
cells were then lysed using 150 .mu.L of M-PER (by PIERCE).
[0081] Total glutathione was quantified using 100 .mu.L of that
lysate. Specifically, a 96-well plate was charged with 100 .mu.L of
dissolved cell liquid lysate, 50 .mu.L of a 0.1 M phosphate buffer
solution, 25 .mu.L of 2 mM NADPH, and 25 .mu.L of glutathione
reductase (final concentration 17.5 unit/mL), with warming for 10
minutes at 37.degree. C. Next, 25 .mu.L of 10 mM 5,5'-dithiobis
(2-nitrobenzoic acid) were added, and absorbance was measured until
5 minutes thereafter at a wavelength of 412 nm, to work out
.DELTA.OD/min. The total glutathione concentration was calculated
on the basis of a calibration curve plotted using oxidized
glutathione (by Wako Pure Chemical). The obtained values were
corrected to amount of glutathione per total protein amount, and
then the glutathione production promotion rate (%) was calculated
on the basis of the formula below.
Glutathione production promotion rate (%)=B/A.times.100
[0082] In the formula, A denotes "amount of glutathione per total
protein amount in cells with no sample added (control)", and B
denotes "amount of glutathione per total protein amount in cells
with sample added".
[0083] The results are given in Table 1.
TABLE-US-00001 TABLE 1 Sample concentration Glutathione production
Sample (.mu.g/mL) promotion rate (%) 1 6.25 114.9 12.5 128.5 25
145.2 2 6.25 118.1 12.5 151.6 25 188.4 3 6.25 109.9 12.5 129.6 25
142.2
[0084] As Table 1 shows, it was found that the licorice extract
compositions containing liquiritin, liquiritigenin, isoliquiritin
and isoliquiritigenin but containing substantially no glycyrrhizic
acid were able to effectively promote glutathione production in
epidermal keratinocytes.
Experimental Example 2
Test of Glutathione Production-Enhancing Activity in Dermal
Fibroblasts
[0085] The glutathione production-enhancing activity of the
licorice extract compositions obtained above (samples 1 to 3) was
tested on dermal fibroblasts as described below.
[0086] Normal human dermal fibroblasts (NB1RGB) were cultured using
10% FBS-containing .alpha.-MEM, after which the cells were
collected by trypsinization. The collected cells were diluted with
10% FBS-containing .alpha.-MEM, to a cell density of
2.0.times.10.sup.5 cells/mL. Thereafter, a 48-well plate was seeded
with 200 .mu.L of cells per well, and the cells were incubated
overnight.
[0087] After incubation, 200 .mu.L of sample solution dissolved in
1% FBS-containing D-MEM (samples 1 to 3, sample concentration as
per Table 2 below) were added to each well, followed by incubation
for 24 hours. Once incubation was over, the medium was removed from
the wells, and each well was washed with 400 .mu.L of PBS (-). The
cells were then lysed using 150 .mu.L of M-PER (by PIERCE).
[0088] Total glutathione was quantified using 100 .mu.L of that
lysate. Specifically, a 96-well plate was charged with 100 .mu.L of
dissolved cell liquid lysate, 50 .mu.L of a 0.1 M phosphate buffer
solution, 25 .mu.L of 2 mM NADPH, and 25 .mu.L of glutathione
reductase (final concentration 17.5 unit/mL), with warming for 10
minutes at 37.degree. C. Next, 25 .mu.L of 10 mM 5,5'-dithiobis
(2-nitrobenzoic acid) were added, and absorbance was measured until
5 minutes thereafter at a wavelength of 412 nm, to work out
.DELTA.OD/min. The total glutathione concentration was calculated
on the basis of a calibration curve plotted using oxidized
glutathione (by Wako Pure Chemical). The obtained values were
corrected to amount of glutathione per total protein amount, and
then the glutathione production promotion rate (%) was calculated
on the basis of the formula below.
Glutathione production promotion rate (%)=B/A.times.100
[0089] In the formula, A denotes "amount of glutathione per total
protein amount in cells with no sample added (control)", and B
denotes "amount of glutathione per total protein amount in cells
with sample added".
[0090] The results are given in Table 2.
TABLE-US-00002 TABLE 2 Sample concentration Glutathione production
Sample (.mu.g/mL) promotion rate (%) 1 6.25 104.3 25 109.4 50 159.9
2 6.25 106.1 25 121.8 50 173.8 3 6.25 102.9 25 114.3 50 147.2
[0091] As Table 2 shows, it was found that the licorice extract
compositions containing liquiritin, liquiritigenin, isoliquiritin
and isoliquiritigenin but containing substantially no glycyrrhizic
acid were able to effectively promote glutathione production in
dermal fibroblasts.
Experimental Example 3
Test of Glutathione Production-Enhancing Activity in B16 Melanoma
Cells
[0092] The glutathione production-enhancing activity of the
licorice extract compositions obtained above (samples 1 to 3) was
tested on B16 melanoma cells as described below.
[0093] B16 melanoma cells were cultured using 10% FBS-containing
D-MEM medium, after which the cells were collected by
trypsinization. The collected cells were diluted with 10%
FBS-containing D-MEM, to a cell density of 1.0.times.10.sup.5
cells/mL. Thereafter, a 48-well plate was seeded with 200 .mu.L of
cells per well, and the cells were incubated overnight.
[0094] After incubation, 200 .mu.L of sample solution dissolved in
1% FBS-containing D-MEM medium (samples 1 to 3, sample
concentration as per Table 3 below) were added to each well,
followed by incubation for 24 hours. Once incubation was over, the
medium was removed from the wells, and each well was washed with
400 .mu.L of PBS (-). The cells were then lysed using 150 .mu.L of
M-PER (by PIERCE).
[0095] Total glutathione was quantified using 100 .mu.L of that
lysate. Specifically, a 96-well plate was charged with 100 .mu.L of
dissolved cell liquid lysate, 50 .mu.L of a 0.1 M phosphate buffer
solution, 25 .mu.L of 2 mM NADPH, and 25 .mu.L of glutathione
reductase (final concentration 17.5 unit/mL), with warming for 10
minutes at 37.degree. C. Next, 25 .mu.L of 10 mM 5,5'-dithiobis
(2-nitrobenzoic acid) were added, and absorbance was measured until
5 minutes thereafter at a wavelength of 412 nm, to work out
.DELTA.OD/min. The total glutathione concentration was calculated
on the basis of a calibration curve plotted using oxidized
glutathione (by Wako Pure Chemical). The obtained values were
corrected to amount of glutathione per total protein amount, and
then the glutathione production promotion rate (%) was calculated
on the basis of the formula below.
Glutathione production promotion rate (%)=B/A.times.100
[0096] In the formula, A denotes "amount of glutathione per total
protein amount in cells with no sample added (control)", and B
denotes "amount of glutathione per total protein amount in cells
with sample added".
[0097] The results are given in Table 3.
TABLE-US-00003 TABLE 3 Sample concentration Glutathione production
Sample (.mu.g/mL) promotion rate (%) 1 6.25 108.2 25 167.2 2 6.25
112.8 25 164.3 3 6.25 108.4 25 143.7
[0098] As Table 3 shows, it was found that the licorice extract
compositions containing liquiritin, liquiritigenin, isoliquiritin
and isoliquiritigenin but containing substantially no glycyrrhizic
acid were able to effectively promote glutathione production in B16
melanoma cells.
Experimental Example 4
Test of Glutathione Production-Enhancing Activity in
Hepatocytes
[0099] The glutathione production-enhancing activity of the
licorice extract compositions obtained as described above (samples
1 to 3) was tested on hepatocytes as described below.
[0100] Normal human hepatocytes (Cell System-Hc Cells, by Cell
Systems) were cultured using CS-C serum-free medium (by Cell
Systems), after which the cells were collected by trypsinization.
The collected cells were diluted with CS-C serum-free medium, to a
cell density of 1.0.times.10.sup.5 cells/mL. Thereafter, a 24-well
plate was seeded with 400 .mu.L of cells per well, and the cells
were incubated overnight.
[0101] After incubation, 400 .mu.L of sample solution dissolved in
CS-C serum-free medium (samples 1 to 3, sample concentration as per
Table 4 below) were added to each well, followed by incubation for
24 hours. Once incubation was over, the medium was removed from the
wells, and each well was washed with 400 .mu.L of PBS (-). The
cells were then lysed using 250 .mu.L of M-PER (PIERCE).
[0102] Total glutathione was quantified using 100 .mu.L of that
lysate. Specifically, a 96-well plate was charged with 100 .mu.L of
dissolved cell liquid lysate, 50 .mu.L of a 0.1 M phosphate buffer
solution, 25 .mu.L of 2 mM NADPH, and 25 .mu.L of glutathione
reductase (final concentration 17.5 unit/mL), with warming for 10
minutes at 37.degree. C. Next, 25 .mu.L of 10 mM 5,5'-dithiobis
(2-nitrobenzoic acid) were added, and absorbance was measured until
5 minutes thereafter at a wavelength of 412 nm, to work out
.DELTA.OD/min. The total glutathione concentration was calculated
on the basis of a calibration curve plotted using oxidized
glutathione (by Wako Pure Chemical). The obtained values were
corrected to amount of glutathione per total protein amount, and
then the glutathione production promotion rate (%) was calculated
on the basis of the formula below.
Glutathione production promotion rate (%)=B/A.times.100
[0103] In the formula, A denotes "amount of glutathione per total
protein amount in cells with no sample added (control)", and B
denotes "amount of glutathione per total protein amount in cells
with sample added".
[0104] The results are given in Table 4.
TABLE-US-00004 TABLE 4 Sample concentration Glutathione production
Sample (.mu.g/mL) promotion rate (%) 1 25 104.4 100 111.4 200 114.3
2 25 105.3 100 103.2 200 121.9 3 25 103.6 100 109.2 200 110.6
[0105] As Table 4 shows, it was found that the licorice extract
compositions containing liquiritin, liquiritigenin, isoliquiritin
and isoliquiritigenin but containing substantially no glycyrrhizic
acid were able to effectively promote glutathione production in
hepatocytes.
Experimental Example 5
Test of .gamma.-glutamylcysteine Synthetase mRNA Expression
Promotion Activity in Epidermal Keratinocytes
[0106] The .gamma.-glutamylcysteine synthetase mRNA expression
promotion activity of the licorice extract compositions obtained
above (samples 1 to 3) was tested on epidermal keratinocytes as
follows.
[0107] Normal human epidermal keratinocytes (NHEK) were cultured
using a culture medium for long-term culture of normal human
epidermal keratinocytes (EpiLife-KG2), after which the cells were
collected by trypsinization. The collected cells were diluted with
EpiLife-KG2, to a cell density of 1.0.times.10.sup.5 cells/mL,
after which 35 mm Petri dishes were seeded each with 2.5 mL of the
cells, which were incubated overnight.
[0108] After incubation, 2.5 mL of sample solution dissolved in
EpiLife-KG2 (samples 1 to 3, sample concentration according to
Table 5 below) was added, and incubation continued a further 16
hours. Once incubation was over, the culture medium was discarded
and total RNA was extracted using ISOGEN (by Nippon Gene, Cat. No.
311-02501). The respective RNA amounts were measured using a
spectrophotometer, and total RNA was adjusted to 200 .mu.g/mL.
[0109] The expression level of mRNA for .gamma.-glutamylcysteine
synthetase and GAPDH, as an internal standard, were measured using
the above total RNA as a template. Detection was performed by
real-time 2-step RT-PCR using a TaKaRa SYBR PrimeScript.TM. RT-PCR
Kit (Perfect Real Time, code No. RR063A), in a real-time PCR device
Smart Cycler (by Cepheid). The expression level of mRNA of
.gamma.-glutamylcysteine synthetase was corrected by the expression
level of mRNA of GAPDH in the same sample. Thereafter, the
corrected value of "with sample added" was calculated taking 100 as
the corrected value of "with no sample added". The mRNA expression
promotion rate (%) of .gamma.-glutamylcysteine synthetase was
calculated on the basis of the formula below.
mRNA expression promotion rate (%)=B/A.times.100
[0110] In the formula, A denotes "mRNA expression level with no
sample added (control)", and B denotes "mRNA expression level with
sample added".
[0111] The results are given in Table 5.
TABLE-US-00005 TABLE 5 Sample concentration mRNA expression Sample
(.mu.g/mL) promotion rate (%) 1 6.25 241.2 25 891.7 2 6.25 205.6 25
638.2 3 6.25 196.1 25 487.2
[0112] As Table 5 shows, it was found that the licorice extract
compositions containing liquiritin, liquiritigenin, isoliquiritin
and isoliquiritigenin but containing substantially no glycyrrhizic
acid were able to effectively promote expression of
.gamma.-glutamylcysteine synthetase mRNA in epidermal
keratinocytes.
Experimental Example 6
Test of .gamma.-glutamylcysteine Synthetase mRNA Expression
Promotion Activity in Dermal Fibroblasts
[0113] The .gamma.-glutamylcysteine synthetase mRNA expression
promotion activity of the licorice extract compositions obtained
above (samples 1 to 3) was tested on dermal fibroblasts as
described below.
[0114] Normal human dermal fibroblasts (NB1RGB) were cultured using
a 10% FBS-containing .alpha.-MEM, after which the cells were
collected by trypsinization. The collected cells were diluted with
10% FBS-containing .alpha.-MEM down to a cell density of
2.0.times.10.sup.5 cells/mL, after which 35 mm Petri dishes were
seeded each with 2.5 mL of the cells, which were incubated
overnight.
[0115] After incubation, 2.5 mL of sample solution dissolved in 1%
FBS-containing D-MEM (samples 1 to 3, sample concentration
according to Table 6 below) was added, and incubation continued a
further 16 hours. Once incubation was over, the culture medium was
discarded and total RNA was extracted using ISOGEN (by Nippon Gene,
Cat. No. 311-02501). The respective RNA amounts were measured using
a spectrophotometer, and total RNA was adjusted to 200
.mu.g/mL.
[0116] The expression level of mRNA for .gamma.-glutamylcysteine
synthetase and GAPDH, as an internal standard, were measured using
the above total RNA as a template. Detection was performed by
real-time 2-step RT-PCR using a TaKaRa SYBR PrimeScript.TM. RT-PCR
Kit (Perfect Real Time, code No. RR063A), in a real-time PCR device
Smart Cycler (by Cepheid). The expression level of mRNA of
.gamma.-glutamylcysteine synthetase was corrected by the expression
level of mRNA of GAPDH in the same sample. Thereafter, the
corrected value of "with sample added" was calculated taking 100 as
the corrected value of "with no sample added". The mRNA expression
promotion rate (%) of .gamma.-glutamylcysteine synthetase was
calculated on the basis of the formula below.
mRNA expression promotion rate (%)=B/A.times.100
[0117] In the formula, A denotes "mRNA expression level with no
sample added (control)", and B denotes "mRNA expression level with
sample added".
[0118] The results are given in Table 6.
TABLE-US-00006 TABLE 6 Sample concentration mRNA expression Sample
(.mu.g/mL) promotion rate (%) 1 25 122.3 2 162.6 3 139.4
[0119] As Table 6 shows, it was found that the licorice extract
compositions containing liquiritin, liquiritigenin, isoliquiritin
and isoliquiritigenin but containing substantially no glycyrrhizic
acid were able to effectively promote expression of
.gamma.-glutamylcysteine synthetase mRNA in dermal fibroblasts.
Experimental Example 7
Test of .gamma.-glutamylcysteine Synthetase mRNA Expression
Promotion Activity in B16 Melanoma Cells
[0120] The .gamma.-glutamylcysteine synthetase mRNA expression
promotion activity of the licorice extract compositions obtained
above (samples 1 to 3) was tested on B16 melanoma cells as
described below.
[0121] B16 melanoma cells were cultured using 10% FBS-containing
D-MEM medium, after which the cells were collected by
trypsinization. The collected cells were diluted with 10%
FBS-containing D-MEM, to a cell density of 1.0.times.10.sup.5
cells/mL, after which 35 mm Petri dishes were seeded each with 2.5
mL of the cells, which were incubated overnight.
[0122] After incubation, 2.5 mL of sample solution dissolved in 1%
FBS-containing D-MEM medium (samples 1 to 3, sample concentration
according to Table 7 below) was added, and incubation continued a
further 16 hours. Once incubation was over, the culture medium was
discarded and total RNA was extracted using ISOGEN (by Nippon Gene,
Cat. No. 311-02501). The respective RNA amounts were measured using
a spectrophotometer, and total RNA was adjusted to 100
.mu.g/mL.
[0123] The expression level of mRNA for .gamma.-glutamylcysteine
synthetase and GAPDH, as an internal standard, were measured using
the above total RNA as a template. Detection was performed by
real-time 2-step RT-PCR using a TaKaRa SYBR PrimeScript.TM. RT-PCR
Kit (Perfect Real Time, code No. RR063A), in a real-time PCR device
Smart Cycler (by Cepheid). The expression level of mRNA of
.gamma.-glutamylcysteine synthetase was corrected by the expression
level of mRNA of GAPDH in the same sample. Thereafter, the
corrected value of "with sample added" was calculated taking 100 as
the corrected value of "with no sample added". The mRNA expression
promotion rate (%) of .gamma.-glutamylcysteine synthetase was
calculated on the basis of the formula below.
mRNA expression promotion rate (%)=B/A.times.100
[0124] In the formula, A denotes "mRNA expression level with no
sample added (control)", and B denotes "mRNA expression level with
sample added".
[0125] The results are given in Table 7.
TABLE-US-00007 TABLE 7 Sample concentration mRNA expression Sample
(.mu.g/mL) promotion rate (%) 1 25 140.3 2 165.7 3 132.8
[0126] As Table 7 shows, it was found that the licorice extract
compositions containing liquiritin, liquiritigenin, isoliquiritin
and isoliquiritigenin but containing substantially no glycyrrhizic
acid were able to effectively promote expression of
.gamma.-glutamylcysteine synthetase mRNA in B16 melanoma cells.
Experimental Example 8
Test of .gamma.-glutamylcysteine Synthetase mRNA Expression
Promotion Activity in Hepatocytes
[0127] The .gamma.-glutamylcysteine synthetase mRNA expression
promotion activity of the licorice extract compositions obtained
above (samples 1 to 3) was tested on hepatocytes as described
below.
[0128] Normal human hepatocytes (Cell System-Hc Cells, by Cell
Systems) were cultured using CS-C serum-free medium (by Cell
Systems), after which the cells were collected by trypsinization.
The collected cells were diluted with CS-C serum-free medium, to a
cell density of 1.0.times.10.sup.5 cells/mL, after which 35 mm
Petri dishes were seeded each with 2.5 mL of the cells, which were
incubated overnight.
[0129] After incubation, 2.5 mL of sample solution dissolved in
CS-C serum-free medium (samples 1 to 3, sample concentration
according to Table 8 below) was added, and incubation continued a
further 16 hours. Once incubation was over, the culture medium was
discarded and total RNA was extracted using ISOGEN (by Nippon Gene,
Cat. No. 311-02501). The respective RNA amounts were measured using
a spectrophotometer, and total RNA was adjusted to 200
.mu.g/mL.
[0130] The expression level of mRNA for .gamma.-glutamylcysteine
synthetase and GAPDH, as an internal standard, were measured using
the above total RNA as a template. Detection was performed by
real-time 2-step RT-PCR using a TaKaRa SYBR PrimeScript.TM. RT-PCR
Kit (Perfect Real Time, code No. RR063A), in a real-time PCR device
Smart Cycler (by Cepheid). The expression level of mRNA of
.gamma.-glutamylcysteine synthetase was corrected by the expression
level of mRNA of GAPDH in the same sample. Thereafter, the
corrected value of "with sample added" was calculated taking 100 as
the corrected value of "with no sample added". The mRNA expression
promotion rate (%) of .gamma.-glutamylcysteine synthetase was
calculated on the basis of the formula below.
mRNA expression promotion rate (%)=B/A.times.100
[0131] In the formula, A denotes "mRNA expression level with no
sample added (control)", and B denotes "mRNA expression level with
sample added".
[0132] The results are given in Table 8.
TABLE-US-00008 TABLE 8 Sample concentration mRNA expression Sample
(.mu.g/mL) promotion rate (%) 1 50 110.5 2 138.6 3 118.2
[0133] As Table 8 shows, it was found that the licorice extract
compositions containing liquiritin, liquiritigenin, isoliquiritin
and isoliquiritigenin but containing substantially no glycyrrhizic
acid were able to effectively promote expression of
.gamma.-glutamylcysteine synthetase mRNA in hepatocytes.
[0134] The above-described Experimental examples 1 to 4 show that
the licorice extract compositions containing liquiritin,
liquiritigenin, isoliquiritin and isoliquiritigenin but containing
substantially no glycyrrhizic acid have excellent glutathione
production-enhancing activity. Also, Experimental examples 5 to 8
show that the licorice extract compositions containing liquiritin,
liquiritigenin, isoliquiritin and isoliquiritigenin but containing
substantially no glycyrrhizic acid have excellent
.gamma.-glutamylcysteine synthetase mRNA expression promotion
activity. These indicate that, thanks to the
.gamma.-glutamylcysteine synthetase mRNA expression promotion
activity, the licorice extract compositions containing liquiritin,
liquiritigenin, isoliquiritin and isoliquiritigenin but containing
substantially no glycyrrhizic acid promote the biosynthesis of
.gamma.-glutamylcysteine, which is a glutathione precursor, and
promote as a result in-vivo production of glutathione.
Experimental Example 9
Measurement of the Amount of Glutathione in Farmed Fish
[0135] There was measured the amount of glutathione in muscle
tissue of fished farmed under the conditions below, using the
licorice extract composition (sample 1) obtained in Preparation
example 1 as a fish-farming feed.
[0136] (1) Test fish: farmed red seabream averaging 1 kg
[0137] (2) Test period: September to October
[0138] (3) No. of fish tested: 10/6000 (free fish)
[0139] (4) Administration amount: 20 mg of sample 1/kg fish
weight
[0140] (5) Administration method: feeding for 4 days, 3 days rest
(over one month)
[0141] (6) Measurement date: one month after start of the test
[0142] The amount of glutathione in muscle tissue of farmed fish
was measured as follows.
[0143] Muscle (back) of farmed red seabream in the administration
group of sample 1 was homogenized with 5% 5-sulfosalicylic acid,
and was then centrifuged at 4.degree. C. The supernatant was used
as the sample solution. A 96-well plate was charged with 25 .mu.L
of the sample solution, and 125 .mu.L of a 0.1 M phosphate buffer
solution. Next, 25 .mu.L of 10 mM 5,5'-dithiobis (2-nitrobenzoic
acid) were added, and absorbance was measured until 5 minutes
thereafter at a wavelength of 412 nm, to work out .DELTA.OD/min.
The reduced glutathione concentration was calculated using a
calibration curve prepared using a reduced glutathione standard. In
a control group, the reduced glutathione concentration was
measured, in the same way, in muscle (back) of farmed red seabream
grown under the same conditions as above, but without
administration of sample 1.
[0144] The results are given in Table 9.
TABLE-US-00009 TABLE 9 Glutathione amount (mg/100 g muscle) Sample
1 administration group 11.1 Control group 8.9
[0145] As Table 9 shows, it was found that a licorice extract
composition containing liquiritin, liquiritigenin, isoliquiritin
and isoliquiritigenin but containing substantially no glycyrrhizic
acid had an effect of effectively increasing the amount of
glutathione in muscle of farmed red seabream.
Experimental Example 10
Measurement of Amount of Glutathione in Mouse Skin
[0146] HR-1/Hos five-week-old female hairless mice (from Hoshino
Laboratory Animals) were acclimatized for one week, and were then
fed a mixture of licorice extract composition (sample 1) obtained
in Preparation example 1 and a powder sample (Labo-MR stock, by
Shimizu Laboratory Supplies). Feeding continued daily for three
weeks at a daily ingestion amount of licorice extract composition
(sample 1) of 50 (mg/kg of mouse body weight). Once feeding was
over, the skin was sampled and was solubilized, using a Teflon
homogenizer, in 100 .mu.L of PBS containing 1% of TritonX-100, per
1 mg of skin, and was centrifuged at 4.degree. C. (12000 rpm, 15
min). The supernatant was used as the measurement sample.
[0147] Total glutathione was determined using 25 .mu.L from the
obtained measurement sample. Specifically, a 96-well plate was
charged with 25 .mu.L of measurement sample, 125 .mu.L of a 0.1 M
phosphate buffer solution, 25 .mu.L of 2 mM NADPH, and 25 .mu.L of
glutathione reductase (final concentration: 17.5 unit/mL), with
warming for 10 minutes at 37.degree. C. Next, 25 .mu.L of 10 mM
5,5'-dithiobis (2-nitrobenzoic acid) were added, and absorbance was
measured until 5 minutes thereafter at a wavelength of 412 nm, to
work out .DELTA.OD/min. The total glutathione concentration was
calculated, as the amount of glutathione per weight of skin, from a
value calculated on the basis of a calibration curve plotted using
oxidized glutathione (by Wako Pure Chemical). In a control group,
the total glutathione concentration in mouse skin was calculated in
the same way as above, but without addition of licorice extract
composition (sample 1) to the powder feed.
[0148] The results are given in Table 10.
TABLE-US-00010 TABLE 10 Glutathione amount (mg/100 g skin) Sample 1
administration group 38.0 Control group 23.6
[0149] As Table 10 shows, it was found that a licorice extract
composition containing liquiritin, liquiritigenin, isoliquiritin
and isoliquiritigenin but containing substantially no glycyrrhizic
acid had an effect of effectively increasing the amount of
glutathione in mouse skin.
Blending Example 1
[0150] A mixed feed having the composition below was prepared in
accordance with ordinary methods.
[0151] Licorice Extract Composition
TABLE-US-00011 (Preparation example 1) 1 wt % Fish meal 75 wt %
Wheat flour 10 wt % Starch 7 wt % Fish oil 3 wt % Minerals 2 wt %
Vitamins 2 wt %
Blending Example 2
[0152] Tablets having the composition below were prepared in
accordance with ordinary methods.
[0153] Licorice Extract Composition
TABLE-US-00012 (Preparation example 1) 30.0 mg Whey minerals 100.0
mg (containing 25 to 30% calcium) Vitamin K.sub.2 (1% powder) 1.5
mg Maltitol 156.0 mg Glycerin fatty acid ester 12.5 mg
Blending Example 3
[0154] Tablets having the composition below were prepared in
accordance with ordinary methods.
[0155] Licorice Extract Composition
TABLE-US-00013 (Preparation example 2) 15.0 mg Dolomite 83.4 mg
(calcium 20%, magnesium 10%) Casein phosphopeptide 16.7 mg Vitamin
C 33.4 mg Maltitol 126.8 mg Collagen 12.7 mg Sucrose fatty acid
ester 12.0 mg
Blending Example 4
[0156] Capsules having the composition below were prepared in
accordance with ordinary methods. The capsules used were #1 hard
gelatin capsules.
[0157] <Composition of 1 Capsule (200 mg)>
[0158] Licorice Extract Composition
TABLE-US-00014 (Preparation example 2) 20.0 mg Cornstarch 60.0 mg
Lactose 100.0 mg Calcium lactate 10.0 mg Hydroxypropyl cellulose
(HPC-L) 10.0 mg
Blending example 5
[0159] An oral liquid preparation having the composition below was
prepared in accordance with ordinary methods.
[0160] <Composition of One Ampoule (100 mL)>
[0161] Licorice Extract Composition
TABLE-US-00015 (Preparation example 3) 0.4 wt % Sorbitol 12.0 wt %
Sodium benzoate 0.1 wt % Fragrance 1.0 wt % Calcium sulfate 0.5 wt
% Purified water balance
INDUSTRIAL APPLICABILITY
[0162] The glutathione production enhancer of the present invention
allows preventing, treating or improving skin aging, blemishes,
damage from oxidative stress caused by ultraviolet radiation, and
diseases caused by glutathione deficiency (for instance, diseases
caused by oxidative stress from reactive oxygen species or the
like; liver diseases such as hepatitis and liver dysfunction;
chronic renal failure; respiratory diseases such as idiopathic
pulmonary fibrosis or adult respiratory syndrome; cataracts;
ischemic heart disease; Parkinson's disease; Alzheimer's disease;
gastrointestinal diseases such as gastric ulcer; cancer; bone
marrow aplasia; acquired immunodeficiency syndrome; latent viral
infections and the like) and also sleeps disorders, such as
insomnia, that are caused by oxidized glutathione deficiency.
* * * * *